Attention aspiring ufologists: July 2 is World UFO Day.It's a day to raise awareness of what some think are extraterrestrial visits to our planet. The day roughly corresponds to the date of perhaps the most well-known UFO story.In July 1947, debris was discovered on a ranch northwest of Roswell, N.M., that some think came from an alien spacecraft. Eye witnesses claimed they saw alien bodies at the crash site.